Pipes used to transport fluids in wells sometimes need to be well insulated to ensure the fluid remains above a certain temperature without need for further heating. When the fluid is a liquid, high temperatures may be useful, as high temperature liquids may have a lower viscosity than lower temperature liquids. The necessary insulation is typically provided in double-walled pipes having an inner tube section, an outer tube section, and a thermal insulation layer provided between the inner tube section and the outer tube section. Such pipes are generally referred as pipe-in-pipe insulated tubings.
Some other pipes are used as casings to ensure the well integrity. In such a case, insulated pipe-in-pipe casings could be used to avoid heat exchange between the fluid flowing in the tubing and the ground. For instance, in order to avoid permafrost melting.
When it is required to transport the fluid from within the ground to the surface, the objective of insulated tubings is typically to avoid wax or hydrates formation or to protect the well integrity from temperature increases which may cause permafrost melting or annular pressure build up. When it is required to transport steam from the surface to downhole, the objective is to ensure the highest steam quality downhole. For manufacturing, transport and logistical reasons, pipes are typically manufactured in sections, and then joined together by screwing to form longer pipe sections as required.
U.S. Pat. No. 8,061,739 B2 discloses a thermal insulation device of a screwed junction between two sections of pipe.
The present disclosure seeks to provide an alternative to pipes or pipe junctions of the prior art.